Not Applicable.
Not Applicable.
This invention relates to ethylene-olefin polymers, processes for their production, and uses thereof as low molecular weight liquid or wax-like products.
Increasing demand in the oil industry has created a need for a high performance synthetic base oils with low volatility and high oxidative stability. Currently, poly-alpha-olefins (PAO) are used as synthetic base oils but costs are high. This has created a demand for a low cost alternative to PAO such as synthetic hydrocarbons with equivalent or better properties. The present invention is based, in part, on the surprising and unexpected discovery that synthetic base oils may be formulated directly into motor oils or fractionated into different viscosity grade oils with properties equivalent to commercial PAO.
Various prior art publications are available relating to poly-alpha-olefin polymers. Reference may be made to U.S. Pat. Nos. 4,668,834, 4,542,199, 5,446,221, 4,704,491, 4,377,720, 4,463,201, 4,769,510, 4,404,344, 5,321,107, 5,151,204, 4,922,046, 4,794,096, 4,668,834, 4,507,515, and 5,324,800. Many of these prior art patents involve polymerization of ethylene or poly-alpha-olefins using a catalyst combination comprising a transition metal complex and an aluminoxane.
The present invention provides polymers of poly-olefins which have a high viscosity index, low pour point, low cold cranking viscosity, high fire point and excellent oxidation stability.
It is accordingly an object of the present invention to provide a novel series of ethylene-olefin copolymer and terpolymer compositions useful as base oils for the production of synthetic lubricating oils.
A further object of the invention is to provide a process for the production of copolymers of ethylene and olefins and the resulting polymers which have a high viscosity index, low pour point, and low cold cranking viscosity.
A still further object of the present invention is to provide a process for the preparation of terpolymers of ethylene, an olefin and a third monomeric reactant, which terpolymers have unique characteristics as synthetic base oils.
An even further object of the present invention is to provide a series of novel polymeric products obtained by thermal cracking of the copolymers and terpolymers of the invention and processes for the production therefor.
A still further object of the invention is to provide a series of polymeric products which are the hydrogenated products of the thermal cracking procedure and processes for the production thereof.
A further object of the invention is to provide synthetic base oils for the production of synthetic lubricants.
A further object is to provide novel liquid and wax-like products for the cosmetic, textile, household, and personal care industries.
Further objects and advantages of the present invention will become apparent as the description thereof proceeds.
In satisfaction of the foregoing objects and advantages, the present invention provides a process for the production of an ethylene-olefin copolymer, comprising the steps of:
a) polymerizing ethylene and at least one olefin in the presence of a cocatalyst combination comprising a compound of a transition metal of Group IVb of the Periodic Table and an aluminoxane to produce a copolymer; and optionally,
b) subjecting at least a portion of said copolymer to thermal cracking to produce a cracked hydrocarbon, or hydroisomerizing said copolymer to produce an isomerization hydrocarbon product.
The present invention also provides novel copolymers obtained from the polymerization process and the novel thermally cracked product. The present invention also includes hydrogenation of the polymer obtained from the thermal cracking process to produce a hydrogenated copolymer.
The copolymer produced by the reaction of ethylene and an olefin in the process of the invention may be characterized as follows:
(a) % ethylene of from 50 to 75%;
(b) molecular weight of  less than 2000;
(c) molecular weight distribution of  less than 2.5;
(d) bromine number of  less than 53;
(e) a head to tail molecular structure; and
(f) a pour point of below about 0xc2x0 C.
In a further embodiment, the present invention also provides a process for the production of a terpolymer by reaction under polymerization conditions of ethylene, at least one olefin monomer different from ethylene, and at least one third monomer comprising an ethenically unsaturated hydrocarbon such as an olefin having a carbon chain length of greater than three, in the presence of a catalyst combination comprising a compound of a transition metal of Group IVb of the Periodic Table and an aluminoxane. Also provided is the novel terpolymer produced as a result of this process. This novel terpolymer may also be thermally cracked and hydrogenated, or hydroisomerized.